Incidence and Associated Factors of Delirium in Elderly Patients with Hip Fractures at Nan Hospital

Abstract

Background: Delirium is a psychiatric disorder  caused by acute physical illness, which, if left  untreated, may increase morbidity and mortality.  Studies on delirium in older adults with hip  fractures in Thailand have mainly been conducted  in university hospitals in Bangkok and have  focused only on the postoperative period. Data  from regional hospitals remain limited.
Objective: To determine the incidence and  associated factors of delirium in older adults with  hip fractures treated at Nan Hospital, both  preoperatively and postoperatively, including non-surgical cases.
Materials and Methods: This prospective observational cohort study included patients aged ≥60 years with hip fractures from low-energy  trauma admitted to Nan Hospital between  November 1, 2023, and November 30, 2024.  Exclusion criteria were fractures due to malignancy or other pathology, multiple fractures, or delirium ≤1 month before injury. Delirium was  assessed within 24 hours of admission and once daily pre- and postoperatively for 4 days using the  Thai 3D-CAM, confirmed by DSM-5 criteria. Baseline, preoperative, and postoperative data  were collected. Comparisons between delirium and non-delirium groups were analyzed using  Fisher’s exact test, t-test, and Mann–Whitney U  test. Associated factors were examined using  univariate logistic regression.
Results: Of 242 patients, 220 were enrolled (mean age 80.3±8.1 years; 74.5% female). Delirium  occurred in 11.8% (26/220), including 22.2% in  non-surgical patients (2/9) and 11.4% in surgical  patients (24/211), with equal preoperative and  postoperative incidence (5.7% each). Significant  factors included male sex, age ≥80 years, hearing  impairment, prior delirium, medical comorbidities, preoperative fever, preoperative pain score >5,  and anemia. The strongest associations were prior delirium (OR 12.5, 95%CI 2.0–78.9), hearing  impairment (OR 5.3, 95%CI 2.0–14.2), and male sex (OR 5.1, 95%CI 2.2–11.9). In surgical patients, key  factors were prior delirium (OR 37.2, 95%CI 3.1–445.7), postoperative hyponatremia (OR 15.2, 95%CI 3.0–78.6), and postoperative fever (OR 13.0,  95%CI 3.6–46.2).
Conclusion: Delirium occurred in 11.8% of older  adults with hip fractures. Key associated factors  were prior delirium, hearing impairment, male  sex, high pain score, fever, anemia, age ≥80 years,  and comorbidities. Postoperative delirium (5.7%)  was associated with prior delirium, hyponatremia,  postoperative fever or pneumonia, male sex,  hearing impairment, additional treatments, and  age ≥80 years.